“We do have credible information that he was involved in a verbal altercation with soldiers from his unit just prior to him allegedly opening fire,” Army CID spokesman Chris Gray said late Friday.

One of the witnesses to that altercation was Sgt. Jonathan Westbrook, who was wounded in the shooting.

Sgt. Westbrook told his father Ivan Lopez came into the office to pick up a form to request time off, but was told to come back later.

Lopez returned with a gun and started firing.

“The first guy he shot right in front of my son was killed, and then he turned the gun towards Jonathan, aimed it, and fired. I don’t know how many times he fired, but he hit my son four times,” Westbrook says.